Cataracts – Symptoms & Causes

What are Cataracts?

Cataracts are a common eye disease which occurs due to the clouding of the lens inside the eyes. As a result, a person has blurred vision and is not able to see around clearly. The lens inside the eye in normal conditions provides clear vision, but over time it becomes cloudy which in turn makes it difficult for light to pass through the retina and focus properly resulting in blurred sight.

Nearly half of US citizens aged 80 years or older have cataracts or had surgery to get rid of cataracts permanently.¹

The cloudiness of the lens develops and increases over time if left untreated. Cataracts can even lead to complete vision loss if not treated. In most cases, if one eye is affected with cataracts there are high chances it can affect the second eye too. Cataract surgery is the only effective way to treat cataracts nowadays. Cataract surgery is very safe and corrects the vision problem caused by cataracts.

Importance of Clear Vision

Persons living with cataracts find difficulty in performing daily tasks. The cloudy lens results in blurred vision that becomes worse if left untreated for a long time. While cataracts can be removed with surgery, it is important to understand the value of clear vision and why it is necessary:-

1. Early Detection of Eye Conditions

Clear vision helps us to notice any changes to our eyesight promptly, which in turn helps in the early detection of any eye condition such as glaucoma, macular degeneration, and diabetic retinopathy for effective treatment. A person should undergo regular eye checkups to identify potential issues before progressing.
2. Prevention of Eye Strain

Clear vision helps to prevent eye strain by allowing one to focus accurately and comfortably on tasks like reading, writing, using digital screens, and performing daily activities. Healthy eyes have a clear vision, and reduced muscle fatigue, and discomfort. To minimize the effort exerted by eye muscles ensure eyes are properly aligned with clear vision and lighting, and keep a safe distance from the screens, and printed materials.

3. Safety and Mobility

Clear vision ensures safety and mobility for individuals by perceiving their surroundings accurately and they can react instantly to potential hazards. With clear vision, people can drive safely, read signals clearly, and identify obstacles, and changes in terrain during driving, walking, or engaging in any other activity. You can recognize the facial expressions of others while communicating which in turn helps in facilitating better communication and social interactions

4. Academic and Professional Success

To make the academic and professional journey successful, a clear vision plays an important role in helping individuals to effectively absorb, process, and communicate information. During the academic journey clear vision ensures students can read over textbooks and digital screens, and do not face any difficulty in writing. In sports also, clear vision helps to react fast. Athletes can track moving objects, opponents, or markers on the fields. Visual acuity helps in quick and split-second decisions in the game.

Symptoms of Cataracts

Cataract symptoms often develop gradually. It is important to be aware of cataract signs and symptoms for timely intervention to maintain clear vision. Below is the list of cataract symptoms to look out for to gauge if you have cataracts:-

a. Blurred Vision:- Blurred vision is the most common symptom of cataracts. In the initial stage, the patient notices that his vision becomes cloudy, very similar to looking into foggy or frosted glasses. Patients find difficulty in seeing in low light conditions or when trying to focus on distant objects.

b. Difficulty in seeing at night:- Cataracts cause sensitivity to glare from lights, such as headlamps or street lamps. The person affected by cataracts finds difficulty while driving at night due to reduced contrast and clarity. The increased sensitivity can also cause seeing halos around lights.

c. Frequent Changes in Glasses Prescription:- Patients affected with cataracts will experience more often prescription changes in glasses or contact lenses because clouding of the lens alters the light entering your eye, which requires adjustment to correct the vision. These conditions increase as the cataracts progress and are left untreated.

d. Colors Appear Faded or Yellowish:- A person affected by cataracts may also experience changes in seeing colours. The colours will appear less vibrant, faded, yellowish or brownish tint. A person may experience difficulty in distinguishing different colours when affected by cataracts.

e. Double Vision in One Eye:- Another symptom of cataracts is double vision or multiple images in one eye. When light enters the cloudy lens it scatters the light which results in overlapping the images.

f. Difficulty with Reading and Close-up Tasks:- Patients affected by cataracts experience difficulty in reading small printed texts or focusing on near objects. They will require extra lights for brightness and magnifying glasses to see clearly.

g. Decreased Contrast Sensitivity:– Cataracts reduce the sensitivity to contrast due to which the ability to distinguish between shades of colors or textures is reduced. Due to decreased sensitivity, a person finds it harder to see objects against the background.

h. Seeing “Halos” Around Lights:- People with cataracts see halos or rings around lights in low light conditions, especially at night. These halos interfere with night vision and a person finds difficulty in judging the distances accurately.

i. Vision Improvement with Brighter Light:- During the initial stage of cataracts, patient vision improves temporarily when the environment is well-lit. This is due to the brighter light helping to compensate for the cloudy lens temporarily.

j. Impaired Depth Perception:- Person affected by cataracts finds difficulty in judging distance accurately. Cataracts affect depth perception which can impact daily activities like climbing stairs, playing sports, driving, or swimming where accurate perception is necessary for safety and performance.

Types of Cataracts

Understanding different types of cataracts helps in seeking appropriate treatment. Below is the overview of the types of cataracts:-

1. Age-Related Cataracts

Age-related cataracts are the most common types of cataracts that are diagnosed in individuals. These types of cataracts develop slowly with age. The main reason for age-related cataracts is the changes of proteins in the eye’s lens due to which it becomes cloudy or opaque. Age-related cataracts can be diagnosed in a single eye or both eyes and people are more likely to be diagnosed with cataracts as they get older.

2. Congenital Cataracts

Congenital cataracts are present in individuals either from birth or develop shortly after birth. The main reasons for the development of congenital cataracts could be due to genetic factors, infection caused during pregnancy, or trauma. Congenital cataract requires early intervention for treatment as it affects the baby’s vision development. If not treated on time, congenital cataracts could lead to permanent loss of eyesight.

3. Traumatic Cataracts

Traumatic cataracts are caused due to injury to the eye. Traumatic cataracts could develop immediately after the eye injury or may develop after several months, or years later. The severity of cataracts depends upon the extent of injury. To prevent traumatic cataracts one should be careful while working and should wear protective eyewear when engaged in any activity where there is a risk of eye injury, wear seat belts while driving, handle hazardous materials carefully, be cautious with sharp objects, regular eye exams etc.

4. Secondary Cataracts

Secondary cataracts result from other health issues, conditions, or treatment complications. Secondary cataracts do not develop directly but are caused due to other eye conditions. For example, they can develop after surgery for glaucoma or retinal detachment. Secondary cataracts can also develop due to prolonged use of certain medications or steroids especially when they are used in the form of eye drops or systemic medications.

5. Radiation Cataracts

Radiation cataracts develop when the patient is exposed to high doses of ionizing radiation. Individuals are exposed to radiation during radiation therapy treatment for cancers. Individuals who are working in high radiation zones also have a chance to get affected by cataracts even after months or years. Radiation cataracts can develop in single or both eyes. Always follow safety protocols while working with radiation to minimize unnecessary exposure.

6. Diabetic Cataracts

Diabetic cataracts develop in individuals with high blood sugar levels, particularly in people with diabetes. High blood sugar levels if not controlled over time or ignored for a long time can cause changes in the lens proteins and can lead to diabetic cataracts at an earlier age.

Regardless of the type of cataracts, regular eye exams are necessary for early detection of cataracts and treatment. Depending upon the severity of cataracts, treatment options also vary which include corrective lenses, changes in eyeglasses prescription, or replacement of natural lens with artificial lens through surgical process. Next, we will see the main causes of cataracts.

Top 10 Causes of Cataracts

Understanding the causes of cataracts helps individuals to prevent the same by taking preventive measures and managing eye health effectively. Below are the top 10 causes of cataracts-

1. Age -Aging is the primary cause of cataracts. As we grow older, protein changes within the eye lens occur leading to cloudiness or opacity.
   
2. UV Radiation –If you are exposed to prolonged ultraviolet (UV) radiation from sunlight over many years, it can lead to cataracts. The best way to prevent UV radiation is to wear sunglasses which block UV rays and as a result, prevent cataracts.
   
3. Diabetes – Increased blood sugar levels which are managed poorly can be the potential cause of diabetic cataracts. Elevated blood sugar levels can damage the lens of the eye over time if left untreated.
   
4. Smoking – Individuals who smoke or have a smoking history have a potential risk of developing cataracts. There are hundreds of harmful chemicals present in tobacco smoke and they can lead to the formation of cataracts and other eye diseases.
   
5. Trauma or Injury – Any eye injury or trauma can lead to the formation of cataracts immediately or years later. It is best to wear protective eye gear while working if you have the risk of potential eye injury at the workplace, maintain a safe distance, and keep children away from sharp objects.
   
6. Genetics – Cataracts can also be caused due to genetics. Certain genetic mutations or predispositions increase the chances of developing cataracts. Individuals having a family history of cataracts have a higher chance of getting diagnosed with cataracts.
   
7. Medications – Long-term use of certain drugs such as prednisone² or other steroids can lead to eyesight problems. These drugs can increase the risk of developing cataracts by altering the structure of the lens proteins.
   
8. Radiation Therapy or Eye Surgery – Radiation therapy which is performed at the head or neck region to treat cancer can damage the eye lens over time and can be the potential cause of cataracts.
   
9. Poor Nutrients and Unhealthy Diet – An unbalanced diet which lacks antioxidants and essential nutrients, such as vitamins C and E, which play an important role in keeping eyes healthy their deficiency can lead to the development of cataracts.
   
10. Other Health Conditions – Any secondary health conditions such as hypertension, obesity, excessive cortisol production, myopia, etc. increase the risk of cataracts in individuals.

How to prevent Cataracts?

While ageing and other factors such as UV rays, trauma, smoking, etc which we discussed are the causes of cataracts if we adopt a few preventive measures we can reduce the likelihood of the occurrence of cataracts. Below are a few preventive measures to prevent cataracts:-

1. Protect Your Eyes from UV Radiation

a. Wear sunglasses which are capable of blocking UVA and UVB rays when you are outside, especially in the afternoon during peak sunlight hours.

b. Purchase sunglasses labelled with UV protection, to protect your eyes from harmful ultraviolet radiation.

2. Quit Smoking

a. If you are a smoker, quitting smoking will reduce your chances of developing cataracts and other eye diseases.

b. Smoking leads to cell damage and oxidative stress in the lens of the eyes, which accelerates the formation of cataracts at an early age.

3. Eat Healthy & Balanced Diet

a. Consume a healthy diet which is rich in proteins, vitamins, and antioxidants. Include fresh fruits and vegetables, which are high in fibre and contain vitamins C & E.

b. Antioxidants help in recovering damage caused by oxidants and help in slowing down the progression of cataracts.

4. Control Diabetes and Manage Blood Sugar Levels

a. If you have diabetes, or have a family history of diabetes, then it is important to control your blood sugar levels through healthy eating, exercise, and medication.

b. If you have uncontrolled blood sugar levels then it can lead to accelerated cataract formation.

5. Maintain a Healthy Weight

a. Maintaining a healthy weight according to your age is necessary to decrease the chances of developing cataracts and other health complications.

b. Obesity and overweight increase the risk of developing cataracts. To maintain a healthy weight you should do regular workouts, eat a balanced diet, and avoid junk and processed foods. Read Top 10 foods not to eat after Cataract Surgery to avoid if you had cataract surgery.

6. Limit Alcohol Consumption

a. Regular and excessive alcohol consumption depletes antioxidants in the body and increases the risk of developing cataracts.

b. Limit your alcohol consumption or avoid it altogether to protect your eyes.

7. Protect Your Eyes from Injury

a. Ensure to wear protective eye gear when working in an environment where the risk of eye injury poses such as working with hazardous materials, sports and other places.

b. Eye injuries can lead to the development of cataracts, so precaution is very necessary to prevent them.

Reviewed By

Dr. Sonam Aggarwal
MBBS, MD(C.Medicine)

1. https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/cataracts ↩︎
2. https://www.nhs.uk/medicines/prednisolone/side-effects-of-prednisolone-tablets-and-liquid/ ↩︎